Cogan syndrome

Overview

Cogan syndrome is a rare autoimmune disorder characterized primarily by inflammation of the eyes and inner ears. It most commonly presents as interstitial keratitis (a type of corneal inflammation) combined with audiovestibular symptoms such as hearing loss, tinnitus, and vertigo. In some cases, systemic involvement may occur, affecting blood vessels and leading to complications like aortitis and vasculitis. Cogan syndrome typically affects young adults, though it can appear at any age. Prompt diagnosis and treatment are essential to prevent permanent vision or hearing loss and to manage systemic complications.

Causes

The exact cause of Cogan syndrome is unknown, but it is believed to be an autoimmune condition in which the immune system mistakenly attacks tissues of the eye and inner ear. Possible contributing factors include:

• Autoimmune response: Likely the result of cross-reactivity between infectious agents and host tissues

• Post-infectious trigger: Some patients report preceding respiratory infections before symptom onset

• Genetic predisposition: Although rare, a familial tendency may exist in some cases

Cogan syndrome is not inherited, and it is not considered a contagious condition.

Symptoms

Symptoms of Cogan syndrome can vary in severity and may affect only the eyes and ears or involve multiple organ systems. Common signs and symptoms include:

• Ocular symptoms:

  • Redness, pain, and sensitivity to light (photophobia)

  • Blurred vision

  • Interstitial keratitis (non-ulcerative inflammation of the cornea)

  • Conjunctivitis or scleritis in atypical cases

• Inner ear (audiovestibular) symptoms:

  • Sudden or progressive sensorineural hearing loss

  • Vertigo or dizziness

  • Tinnitus (ringing in the ears)

  • Balance disturbances

• Systemic symptoms (in some patients):

  • Fever, fatigue, and weight loss

  • Large vessel vasculitis or aortitis (can mimic Takayasu arteritis)

  • Arthralgia or myalgia

  • Neurological or gastrointestinal symptoms (rare)

Diagnosis

There is no single test to confirm Cogan syndrome; diagnosis is based on clinical presentation and exclusion of other diseases. Key diagnostic steps include:

• Ophthalmologic examination: To identify interstitial keratitis or other inflammatory eye conditions

• Audiologic tests: Hearing tests to assess sensorineural hearing loss

• Vestibular testing: To evaluate balance and inner ear function

• Blood tests: To rule out infectious or systemic autoimmune conditions (e.g., syphilis, lupus, sarcoidosis)

• Imaging studies: MRI or CT scans of the head or chest to evaluate for vasculitis or aortic involvement

• Biopsy (in rare cases): Of affected tissue to confirm vasculitis

“Typical” Cogan syndrome refers to cases with interstitial keratitis and audiovestibular symptoms within a 2-year period. “Atypical” Cogan syndrome may involve other types of ocular inflammation or delayed onset of inner ear symptoms.

Treatment

Early treatment of Cogan syndrome is critical to prevent irreversible vision or hearing loss. Management involves suppressing inflammation and immune system activity. Treatment options include:

• Corticosteroids: High-dose oral or intravenous steroids are the first-line treatment for acute symptoms

• Immunosuppressive agents: Such as methotrexate, azathioprine, or cyclophosphamide for steroid-sparing effect or systemic involvement

• Biologic therapies: TNF-alpha inhibitors (e.g., infliximab) or rituximab may be used in refractory cases

• Supportive therapies:

  • Hearing aids or cochlear implants for persistent hearing loss

  • Antivertigo medications and vestibular rehabilitation for balance issues

  • Topical eye drops or lubricants for ocular symptoms

• Cardiology follow-up: For patients with suspected or confirmed aortitis or large vessel involvement

Prognosis

The prognosis of Cogan syndrome depends on the severity and extent of organ involvement. With timely diagnosis and aggressive treatment, many patients experience significant improvement or remission of symptoms. However, permanent hearing loss is common, even with treatment. Visual outcomes are generally more favorable if ocular inflammation is managed early. Systemic complications, particularly involving the cardiovascular system, may require long-term monitoring. Overall, multidisciplinary care and early intervention play key roles in improving quality of life and preventing long-term complications.